1. Field of the Invention
The present invention relates to a thin-film common mode filter and a thin-film common mode filter array.
2. Description of the Related Art
Common mode filter is a device for suppressing common mode currents that cause electromagnetic interference in parallel transmission lines. The common mode filter has magnetically coupled inductors to remove in-phase noise component.
Thin-film common mode filter miniaturized and highly integrated by forming bilayered thin-film coils between ferrite substrates and by constructing in chip form, and thin film common mode filter array on which a plurality of the filters are mounted, are described in for example, Japanese Patent Publications Nos. 04-364709A, 08-203737A, 08-335517A and 11-054326A.
Generally, in such a thin-film common mode filter constructed in chip form, drawing terminals of outgoing parts from both ends of the thin-film coil are exposed on the side, and then external-connect electrode terminals are formed on the chip side so that they can be connected electrically to the exposed drawing terminals.
Conventional thin-film common mode filter, however, has small drawing terminals. Therefore, it has been a problem of reliability where, in some cases, the external-connect electrode terminal formed on the chip side has an incomplete electrical connection with the drawing terminal.